package contract

import (
	"bytes"
	"errors"
	"fmt"
	"strings"
	"sync"

	"git.ipao.vip/rogee/go-sip/contracts"
	"github.com/santhosh-tekuri/jsonschema/v6"
)

var compiledSchemas sync.Map

// ValidateCurrent checks only the pinned shared HTTP/MQ contract.
// An absent schema is an error; it never falls back to historical bundles.
func ValidateCurrent(surface string, raw []byte) error {
	var name string
	switch surface {
	case "config-read", "task-discovery", "mq":
		name = surface + ".schema.json"
	default:
		return fmt.Errorf("invalid current contract surface %q", surface)
	}
	value, err := jsonschema.UnmarshalJSON(bytes.NewReader(raw))
	if err != nil {
		return fmt.Errorf("decode %s body: %w", surface, err)
	}
	key := "current/" + name
	cached, ok := compiledSchemas.Load(key)
	var schema *jsonschema.Schema
	if ok {
		schema = cached.(*jsonschema.Schema)
	} else {
		schema, err = contracts.CompileCurrent(name)
		if err != nil {
			return err
		}
		actual, _ := compiledSchemas.LoadOrStore(key, schema)
		schema = actual.(*jsonschema.Schema)
	}
	if err := schema.Validate(value); err != nil {
		var validation *jsonschema.ValidationError
		if errors.As(err, &validation) {
			return fmt.Errorf("%s validation failed at /%s", surface, strings.Join(validation.InstanceLocation, "/"))
		}
		return fmt.Errorf("%s validation failed", surface)
	}
	return nil
}